1. Field of the Invention
Present invention relates to a printer head and particularly to an ink jet printer head and a manufacturing method thereof.
2. Description of the Prior Art
Ink jet printer head is usually formed by sequential accumulation of nozzle plate 222 where nozzle 223 has been formed, reserver plate 221 where reserver 220 is formed, channel plate 219 where flow channel 218 is formed, restrictor plate 217 where restrictor 216 is formed, chamber plate 215 forming a chamber 214, and actuator composed of three parts of upper electrode 210, piezoelectric/electrostrictive film 211 and lower electrode 212 as in FIG. 1.
Ink travel path is formed in ink jet printer head by the above formation of such as nozzle 223, reserver 220, flow channel 218, restrictor 216, chamber 214 of mutually different sizes and shapes.
Ink supplied from ink canister (not shown in figure) is reserved in reserver 220 after which it flows into chamber 214 through flow channel 218 whence the reserver 220 formed between flow channel 218 and chamber 214 maintains ink flow speed into chamber 214 to a constant state.
Piezoelectric substance 211 is actuated if voltage is applied at upper electrode 210 and lower electrode 212 of actuator formed upon chamber 214; by which piezoelectric/electrostrictive film 211 actuation the chamber 214 volume momentarily decreases while chamber 214 ink is ejected through nozzle 223 formed at nozzle plate 222 onto material on which to be written. Printing is carried out by this ink jet.
Until now to manufacture an ink jet printer head as described above, use has been made of method of assembling after separately making a nozzle plate where nozzle is formed, a reserver plate where reserver is formed, a channel plate where channel is formed, a restrictor plate where restrictor is formed and a chamber plate where chamber is formed.
In this method, each plate comprising the ink jet printer head as above is manufactured by each separate process, and photoresist is coated on each of these separately manufactured plates which are then exposed to light, after which the guide holes are formed for assembling, then these plates are piled one upon another. Guide holes are fastened by screw etc. to fix the plates which are then thermally treated so that they are bonded together to finish the ink jet printer head.
In this traditional method, there is problem that yield percentage is low because there is large possibility to generate assembly tolerance error owing to inaccurate congruence of the guide hole positions and the plate sizes when assembling. And there is demerit of production cost rise because such photoresist should be used as is excellent in adhesion and low in reactivity with ink, which photoresist is to be coated before bonding the plates together.